sensitisoinnista

Sensitization, or sensitisointi in Finnish, is the immunological process by which the immune system becomes responsive to a normally harmless substance (an allergen). In sensitized individuals, the body produces allergen-specific IgE and primes effector cells such as mast cells and basophils, enabling allergic reactions upon re-exposure. Sensitization is a prerequisite for many allergic diseases but does not by itself cause symptoms. The form sensitisoinnista is the genitive case in Finnish, meaning “from sensitization.”

Most sensitization involves IgE-mediated mechanisms. After an initial exposure, antigen-presenting cells activate T helper 2 cells, promoting B cells to switch to IgE, which binds to FcεRI on mast cells and basophils. On re-exposure, allergen cross-links bound IgE, triggering degranulation and release of histamine, leukotrienes, and other mediators that cause symptoms such as sneezing, itching, wheeze, or urticaria. Some sensitization is non-IgE–mediated, as in delayed-type hypersensitivity seen in contact dermatitis, involving T cells.

Clinical relevance: Sensitization is common in respiratory allergies (rhinitis, asthma), food allergies, and atopic dermatitis. The presence of allergen-specific IgE indicates sensitization but does not fully predict disease; clinical history and symptom patterns are essential for diagnosis and management.

Diagnosis: Skin prick testing and serum tests for allergen-specific IgE are used to detect sensitization. More detailed diagnostics include component-resolved diagnostics for identifying IgE to specific allergen components. Results must be interpreted in the clinical context.

Prevention and management: Avoidance of known triggers, environmental controls, and appropriate pharmacotherapy can manage symptoms. Allergen immunotherapy may reduce sensitization and modify disease in selected patients. Ongoing research explores early-life exposures and personalization of diagnostics and therapy.